The pilot Traumatic Coma Data bank collected information on 581 patients with severe head injuries, drawn from six centers in the United States. These data are being analyzed to identify patterns of injury and type of accident as they vary from center to center, by patient demographic characteristics, season and time of day. By profiling the characteristics of the 58 children in the data bank, it was found that pedestrian accidents (i.e., children who were struck by motor vehicles) were the most frequent cause of injury and that falls were most common among infants and toddlers. The case frequency sex ratio varied with age, being 2:1 (male excess) in children, almost 4:1 in the middle ages, and about 1:1 in the 60-and-older age group. Case fatality rates differed by age, but not by sex. A study submitted for publication focused on the age groups 15-24 years. The typical head injury victim was a young man between the ages of 15 and 24. Sex differences between injury victims in this age group include differences in mechanism of injury, role (driver, occupant, pedestrian) of the injured person, and in alcohol use at the time of accident.